fix: ETU-70902: Set API-spec version automatically (using CalVer convention)

.spectral.yml

@@ -362,16 +362,6 @@ rules:
   # 3.2 Versioning
   # -------------------------------------------------------------------------
 
-  entur-info-version:
-    message: "The OpenAPI info.version MUST be a valid semantic version (MAJOR.MINOR.PATCH format, e.g. 1.0.0)."
-    documentationUrl: "https://github.com/entur/api-guidelines/blob/main/guidelines.md#32-versioning"
-    severity: error
-    given: $
-    then:
-      field: info.version
-      function: pattern
-      functionOptions:
-        match: "^(0|[1-9]\\d*)\\.(0|[1-9]\\d*)\\.(0|[1-9]\\d*)$"
 
   # -------------------------------------------------------------------------
   # 3.3 Backward Compatibility - Not directly lintable
@@ -519,7 +509,7 @@ rules:
 
   entur-language-headers:
     message: "Accept-Language and Content-Language should follow IETF BCP 47. And macrolanguages like 'no' should not be used - use 'nb' or 'nn'."
-    documentationUrl: "https://github.com/entur/api-guidelines/blob/main/guidelines.md#41-language--spelling"
+    documentationUrl: "https://github.com/entur/api-guidelines/blob/main/guidelines.md#51-language--spelling"
     severity: error
     given:
       - $..parameters[?(@.in=='header' && @.name=='Accept-Language')].example

guidelines.md

@@ -282,7 +282,11 @@ Here, only 1 specification will be shown on the Developer Portal, which is a com
   - Example: `https://api.entur.io/sales/v1/orders?distributionChannelId=1`
 
 #### 3.2.2 API Spec Versioning
-- :white_check_mark: The info.version field **MUST** be set and follow the semver format (e.g. `1.0.0`). This field can be used to communicate changes in the api, together with a changelog.
+API spec versioning is done automatically when [publishing the spec](https://github.com/entur/gha-api/blob/main/README-publish.md).
+The version is set based on the [CalVer](https://calver.org/) versioning convention, and uses the format YYYY.MM.MICRO. When the spec is
+published, the current year and month is used, and MICRO is set to "00". If a version already exists for the given year and month, "01" is used (and so on).
+If the published spec is equal to the current spec, no new version is created. Because versioning is done automatically, the value in `info.version` is ignored, 
+but must be set in order for linting to pass, therefore a placeholder value like `1.0.0` may be used.
 
 ### 3.3 Backward Compatibility
 - :eyes: You **MUST** not remove or modify existing fields or endpoints